import React, { Component } from 'react';
import './index.css'

export default class Footer extends Component {


    //全选checkbox的回调
    handleCheckAll = (event) => {
        this.props.checkAllTodo(event.target.checked)
    }

    //清除已完成任务的回调
    handleClearAllDone = () => {
        this.props.clearAllDone();
    }


    render() {
        const { todos } = this.props;

        //已完成的个数
        // const doneCount = todos.filter(todoObj => todoObj.done === true).length;
        const doneCount = todos.reduce((pre, todo) => pre + (todo.done ? 1 : 0), 0)
        //总数
        const total = todos.length;

        return (
            <div className="todo-footer">
                <label>
                    <input type="checkbox" checked={doneCount === total && total > 0 ? true : false} onChange={this.handleCheckAll} />
                    <span>
                        <span>已完成{doneCount}</span>/ 全部{total}
                    </span>
                </label>

                <button className="btn btn-danger" onClick={this.handleClearAllDone}>清除已完成任务</button>
            </div>
        )
    }
}
